Eric Welch

19 Questions 29 Answers 0 Followers

Questions related from Eric Welch

How to rotate a general unit cell to a certain direction??

Given the a, b and c vectors of a general crystal structure (not necessarily cubic, can be say, monoclinic), is there a general rotation matrix formula for taking the (001) surface of the bulk to...

05 October 2021 4,968 9 View

Why does vasp fail when writing wave functions??

During a non-scf band structure calculation in VASP (ICHARG = 11), I have numerous jobs that have failed to complete writing the WAVECAR file (they started fine from the pre-converged CHGCAR, but...

06 September 2021 2,451 2 View

How to add kpoint labels to hybrid functional band structure plot using pymatgen?

I am using the pymatgen Vasprun and BSPlotter classes to plot data from my vasprun.xml file after an HSE06 band structure calculation in VASP (using 0 weight kpoint method). I copied a non-hybrid...

25 August 2021 1,487 0 View

Is there an easy way to keep up with journals containing a specific term or topic??

So, I am familiar with all the normal tools (google scholar, RSS feed, etc) but I was curious if anyone had a clever way to get daily updates from journals containing keyword that were recently...

19 August 2021 1,514 1 View

How to plot pdos of Ga2O3 using Pymatgen modules??

To preface this, I have looked on stack overflow but this topic hasn't been addressed as far as I could find. I am trying to use the Pymatgen vasp modules to plot the element_spd projected dos...

05 August 2021 9,815 3 View

What is the best method for studying thermal transport across an interface using DFT??

As the question states, I'd like to study phonon behavior at the interface of two semiconducting materials (GaN and diamond), using DFT (or DFPT) within the framework of VASP (the program I use)....

13 June 2021 1,935 1 View

How to optimize parallelization in VASP??

My cluster has > 3500 cores, uses linux and infiniband connectivity. What is the most systematic way to determine the best values for NPAR, NCORE, NSIM and KPAR?? I am using the most recent...

31 May 2021 1,524 1 View

Can you include relativistic nuclear effects in VASP??

Is it possible to include the spin interaction of the nucleus with the strong nuclear force (nuclear spin orbit coupling)?? Are there pseudo potential which include these or are there INCAR tags...

23 March 2021 8,347 1 View

Is there a tool to use with the split_dos.py script of VTST tools to plot layer specific DOS for a surface supercell??

I am trying to look at the affect of a surface on the DOS of a supercell (in VASP), and found the nice scripts from the group at UT called VTST tools. The split_dos.py script does exactly what I...

16 November 2020 2,393 5 View

Any advice on running quantum espresso on a single Imac??

I have been using VASP for years now and wanted to try out QE on my home IMac since it's open source. Does anyone have any advice?? I recently wiped and reinstalled the OS on the mac so it is...

30 September 2020 5,503 2 View

What inputs should be included in interface calculations of polar materials using VASP??

I am attempting to study the charge density difference and local potential difference of the interface between wurtzite GaN and cubic diamond using DFT in VASP. I have optimized the bulk...

09 September 2020 2,555 1 View

How to rotate 2d lattices in VESTA??

I am trying to test the coincidence lattice method for the interface between wurtzite (0001) GaN and cubic diamond (111). How do I rotate the two lattices with respect to one another using...

20 August 2020 5,324 1 View

How to create an interface between a wurtzite structure and a cubic zinc blende structure??

I want to create an interface (in VESTA) between cubic (zinc blende) diamond (111 surface) and wurtzite GaN (0002 surface) for a density functional theory/band offset study. Is there a...

09 July 2020 8,257 6 View

Why do different methods in python, result in different values of zero??

I am using numpy in python along with the linalg package to solve for the eigenvalues and eigenvectors of a 2x2 matrix. I also did this by hand, and coded the brute-force algebra step by step to...

24 March 2020 9,653 2 View

What are the units for each constant in the Fröhlich coupling constant formula (when reported in a journal, preferably)??

As the title states, using the following equation to calculate the coupling constant using DFT and experimental values a =...

24 September 2019 8,213 0 View

How to determine core electron energies for band offset calculations??

I am trying to calculate band offsets for two materials (CsPbBr3 and CuI) and I am comparing equal increases in layer thickness. In this paper (Halide Perovskite Heteroepitaxy: Bond Formation and...

30 July 2019 327 0 View

How to rotate POSCAR file to face 111 direction??

I am familiar with VESTA and it's functionality to rotate a cell from a POSCAR (from VASP). I am trying to rotate a cubic unit cell (CH3NH3PbI3) to face the 111 direction but when i use the...

05 April 2019 4,979 3 View

How to parse vasprun.xml file that is too large for p4vasp??

I am currently exploring a 2x2x2 supercell of CH3NH3PbI3 to look at polaron behavior. However, the vasprun.xml file is too large for p4vasp to plot the band structure and DOS plots (500GB+). Are...

10 March 2019 641 6 View

How to plot planar charge density difference plots from VASP outputs??

How does one parse the chg file to plot the planar average charge density for a surface slab using VASP?? I am trying to calculate the planar averaged charge density difference.

19 December 2018 4,147 5 View